Admited to the Union as the 33rd state on Feb. 14, 1859, Oregon comprises an area of startling physical diversity, from the moist rain forests, mountains, and fertile valleys of its western third to the naturally arid and climatically harsh eastern deserts. Mountains, plateus, plains, and valleys of different geologic ages and materials are arrayed in countless combinations, including such natural wonders as the Columbia River Gorge, Oregon Caves National Monument, Crater Lake National Park, the majestic snow-covered peaks of the Cascade Range, and the “moon country” of central Oregon. The name Oregon is thought to be Indian in orgin. To the north of the state’s 97,073 square miles (251,419 square kilometres)of land and inland water lies Washington, from which Oregon receives the waters of the Columbia River; to the east, Idaho, more than half of the border with which is formed by the winding Snake River and its Hells Canyon, the deepest gorge on the North American continent; to the south, Nevada and California, with which Oregon shares its mountain and desert systems; and, to the west, the Pacific Ocean, which produses the moderate climate of Oregon’s western lands. The forested mountains of western and northeastern Oregon have supplied the traditional core of the state’s economy. Its many forest-product plants produce more than one-fith of the nation’s softwood lumber, much of its soft plywood, and large quantites of hardboard, pulp, and paper. Nationally, Oregon ranks first in the production of wood products. In addition, the multipurpose development of the Columbia River system provides huge quantites of electrcity, water for irrigation and industry, shipping channels, and water for recreation. The hearthland the major cities of Portland, Eugene, and Salem (the capital) and a rich diversified agriculture. PHYSICAL AND HUMAN GEOGRAPHY THE LAND.Relief.oregon has nine major landform regions. Of them the forest-blanketed Coast Range, which borders the Pacific Ocean from the Coquile River northward, is the lowest. Its elevations are usually below 2,000 feet, but Marys Peak, southwest of Corvallis, reaches 4,098 feet (1,249 metres).
The Klamath Mountains, which extend from California, lie south of the Coast Range and west of the Cascades. Of ancient resistant rocks, they have had a complicated geologic history. They are higher and more rugged than the Coast Range and lack the north-south orentation. The Rogue River, bisecting the area, provides the major drainage. Thick forests grow on these mountains, which also contain rich mineral deposits. The Willamete valley is essentaly an alluval plain produced burying stream- modifed lowland with enormous quantites of sediments brought down by tributary streams from the bordering mountains. The low, hilly areas in the central and northern poritons are composed of resistant rocks. This valley contains the prime land of the state, and its soils aupport intensive agriculture. The Cascade Range forms a broad lava plateau.the wider western section is deeply eroed by numerousstreams fed by heavy precipitation. The eastern section, less dissected, is crowned with a chain of volcanic peaks. Mount Hood, reaching 11,239 feet (3,428 metres) above sea level, is the higest peak in Oregon, and Mount Jefferson, rising to 10,497 feet(3,199 metres), is the second higest. The Blue Wallowa mountains comprise two higland masses in the northeastern part of the state. The name Blue Mountains refers to the eroded plateus and ranges extending westward from the agriculturally important La Grande and Baker valleys. Basins and valleys, headquarters for large cattle ranches, are scattered throughthe Blue Mountains. The Wallowa Mountains, east of the La Grande and Baker valleys and near the Idaho border, contain the higest elevations in northeastern Oregon. They were heavily glaciated and display spectacular scenery. The area of the High Lava Plains, or High Desert, is located south of the Blue Mountains and eastward from ythe Cascade Range. It is the youngest and least eroded of the landform regions of Oregon, but the smoothness of the surface is broken by cinder cones, buttes, and craters; other features include immatury of erosion and localized interior drainage. Low preciptation, short and eratic growing seasons, and the absence of soil in many places result in an arid landscape of skimpy vegetation, with the details of the surface features commonly visible. The Great Basin of the Basin and Range Province to the south, which merges with the High Lava Plains, has long, narrow, asymmetrical fault block ranges that alternate with wide basins. Small volcanoes are numerous in the western portion, where pumice modifies surface runoff, vegetation, and land use. Irrigation agriculture is practiced in the Upper Klamath Lake area, and hay is grown with irrigation in a number of other basins and valleys, but most of this region is used by range livestock.